Sulfites: What are they and are they safe?

“Contains sulfites” is something you see on almost every bottle of wine, so what does it mean?

Sulfites are a preservative widely used in winemaking because of its antioxidant and antibacterial properties. They play an important role in preventing oxidization and maintaining a wine’s freshness. Sulfites are also found in foods like canned fruits and vegetables, some baked goods and pickled foods.

Sulfites 'generally safe'

The federal Food and Drug Administration (FDA) considers them “generally recommended safe” except for people who have a sensitivity that can cause severe asthma. The FDA estimates that less than 1 percent of the U.S. population is sulfite-sensitive.

Kari Mizgalski a registered dietitian for Marshfield Clinic, doesn’t quibble with the FDA’s stance on sulfite safety but she doesn’t endorse them either.

“Personally, the less additives in food the better. I try to avoid processed foods in general,” she said. “For example, I would use fresh lemon juice rather than juice from a bottle.”

Unnatural addition?

The kitchn, a web magazine devoted to home cooking, noted some people don’t like sulfites because they’re an unnatural addition.

“While that view is valid, it is important to remember sulfites are also a natural byproduct of yeast metabolism during fermentation,” noted the kitchn. “So even if you do not add any additional sulfites, your wine will still contain them.”

Not a major health concern

Mizgalski cross-checked with a nutrition care manual from the Academy of Nutrition and Dietetics and found no worries with sulfites.

“I don’t think sulfites are a big issue,” she said.

The kitchn also addressed a myth that sulfites in wine cause headaches: “There are many other compounds in wine, such as histamines, tannins and the alcohol itself that are more likely connected to the headache effect.”

Allergic reactions can be severe

Mizgalski offered a final thought.

“Sulfites do not have a big impact on health unless you are sensitive to them,” she said. “People allergic to sulfites can have a severe asthmatic reaction but the only way to find out is to drink wine or eat food containing them and have a reaction.”

If you do have a reaction, contact your doctor and have it noted in your medical health record.

This article is part of the "Central to Your Health" series produced by Marshfield Clinic. To find more stories like this, visit Shine365 at Marshfield Clinic.

Members of the editorial and news staff of the USA Today Network were not involved in the creation of this content.